飞机腐蚀损伤构件喷丸强化后的表面残余应力场

Surface Residual Stress Field by Shot Peening on Corroded Aircraft Structural Part

目的研究喷丸方式、飞机构件腐蚀损伤表面形状参数对受喷表面残余应力场的影响。方法以7075铝合金腐蚀损伤飞机构件为研究对象,采用玻璃弹丸作为喷丸介质,通过Abaqus软件建立随机多弹丸有限元模型,获得固定方向喷丸和固定角度喷丸两种喷丸方式下以及不同损伤表面几何形状参数下的表面残余应力场,并通过试验进行验证。结果采用固定角度喷丸能够获得比较均匀的表面残余应力场,而固定方向喷丸时,损伤构件表面不同部位的残余应力存在明显差异。结论在其他参数不变的情况下,弹丸入射角越小,残余压应力越大。应尽量采用垂直撞击方式进行喷丸处理,喷丸处理前清理腐蚀产物时,应形成较为平缓的损伤面过渡区域。

Objective To investigate the effects of impact methods and surface geometric parameters of aircraft corroded parts on residual stress field of the target damaged surface by shot peening. Methods Glass beads and 7075 corrosion damaged civil aircraft structural parts were taken as the research objects, the Abaqus software was adopted and the finite element model of the multiple and random impacts was established. The residual stress fields under the conditions of different impact methods, fixed impact directions and fixed impact incidence angles, and different surface geometric parameters of the damaged parts were obtained. The verified experiments were carried out. Results A nearly uniform residual stress field on the target surface could be achieved by the impact method of fixed impact incidence angle, and the stresses disparities on different regions of the damaged surface existed obviously under the condition of fixed impact direction. Conclusion When the other parameters were invariant, the smaller the incidence angle of impact, the lager the compressive residual stresses on the target surface. It is better to impactthe target surface along its normal direction. A smooth damaged transitional surface should be formed during clearing the corro- sion of the parts before shot peening.